I looked it up and saw there were local elections on October 1. On the national level, the communists are supporting the socialist government. Hard to imagine that happening in any other EU country. In Belem, I saw them advertising the new minimum wage of 600 euros per month.
It is probably similar to what was in Spain, where there were a lot of Anarchist, Anarcho-Communist and other similar groups during Republic, so the tradition is continuing after the change away from Authoritarian regime.